500 species in sixteen genera are found in tropical and subtropical regions.

[Summary yet to be added]

Camellia sasanqua Thunb.

(syn. Thea sasanqua Cels)

Tea Plum

Little (1924) noted that the oil expressed from the seeds of Thea sasanqua — known as tea oil — relieves the itching caused by Chinese lacquer (Toxicodendron vernicifluum F.A.Barkley, fam. Anacardiaceae) and is used by lacquer workers each evening to remove every trace of the varnish from their hands and arms. The usefulness of tea oil for this purpose might be explained by its content of sasanquol, a triterpene alcohol that has been demonstrated to possess anti-inflammatory activity comparable with that of indometacin against 12-O-tetradecanoylphorbol-13-acetate-induced inflammation in mouse ears (Akihisa et al. 1998). 12-O-Tetradecanoylphorbol-13-acetate (TPA) is a potent skin irritant isolated from croton oil (see Croton tiglium L., fam. Euphorbiaceae).

Camellia sinensis Kuntze

(syns Camellia thea Link, Thea sinensis L.)

Tea Plant

Young shoots consisting of buds and two or more leaves are picked and dried to form tea. For scenting Chinese teas, the petals of Chloranthus and Jasminum sambac may be used (Stuart 1911).

Dermatitis in a "tea-boy" whose occupation was the carrying of tea to workers on a construction site was found to be due to alkali dust from the work site (O'Donovan 1927).

Stuart (1911) notes that in Chinese traditional medicine, tea leaves that have been brewed are sometimes put into an earthenware jar and allowed to stand until decomposed. The older and more decomposed they are, the more highly they are esteemed in the treatment of all sorts of ulcers and swellings, dog bites, old burns, and bruises. They are applied as a poultice.

"Water-itch", a vesicular eruption affecting the feet of coolies in the tea gardens of Assam during the wet season, is caused by a mite Rhizoglyphus (Prosser White 1934). Simons (1952) refers to the bites of R. parasiticus as the cause of "tea dermatosis". Caterpillars (Limacodidae) on the tea-plants can cause contact dermatitis (Van Thiel 1953). Workers in tea-plantations suffer wounds on the legs from cut branches of the tea-shrubs, hyperkeratosis of the skin of the index finger from the chemical effect of tea-juice and dew, and vesicular dermatitis of the feet attributed to nitrogenous fertilisers in the soil (Sturua 1957). Processed tea contains small amounts of essential oil which constitutes the odour. The constituents of the oil include geraniol, linalool, benzyl alcohol, phenylethyl alcohol and methyl salicylate (Kariyone 1971). Reactions to salicylate are noted under Betula. Theophylline is present in small amounts in tea. Aminophylline which consists of theophylline and ethylenediamine can cause reactions in ethylenediamine sensitive individuals (Baer et al. 1959, Epstein and Maibach 1968).

Schima noronhae Reinw.

(syn. Gordonia javanica Rollisson ex Hook.)

The sap of this large evergreen tree is said to be irritating to the skin (Corner 1952).